1. Field of the Invention
This invention relates to partition-wall structure for plasma display panels and a plasma display panel having the partition-wall structure.
The present application claims priority from Japanese Application No. 2002-301541, the disclosure of which is incorporated herein by reference.
2. Description of the Related Art
FIG. 1 is a schematic front view illustrating cell structure of a conventional plasma display panel (hereinafter referred to as “PDP”), and FIG. 2 is a sectional view taken along the V—V line in FIG. 1.
The conventional PDP includes a front glass substrate 1, serving as the display screen of panel, having on its back surface, in order, a plurality of row electrode pairs (X, Y), a dielectric layer 2 covering the row electrode pairs (X, Y), and an MgO-made protective layer 3 covering the back surface of the dielectric layer 2.
Each of the row electrodes X and Y is constituted of transparent electrodes Xa or Ya each formed of a transparent conductive film of a larger width made of ITO (Indium Tin Oxide) or the like, and a bus electrode Xb or Yb formed of a metal film of a smaller width assisting the electrical conductivity of the corresponding transparent electrodes.
The row electrodes X and Y are arranged in alternate positions in the column direction such that their transparent electrodes Xa and Ya face each other with a discharge gap g in between. Each of the row electrode pairs (X, Y) forms a display line L in the matrix display.
The front glass substrate 1 is placed opposite a back glass substrate 4 with a discharge-gas-filled discharge space in between. The back glass substrate 4 is provided thereon with: a plurality of column electrodes D regularly arranged and each extending in a direction at right angles to the row electrode pairs (X, Y); a column-electrode protective layer 5 covering the column electrodes D; a partition wall 6 formed in a pattern, which will be described later, for partitioning the discharge space; and red-, green- and blue-colored phosphor layers 7 each formed on the side faces of the partition walls 6 and the column-electrode protective layer 5.
The partition wall 6 is constituted of transverse walls 6A and vertical walls 6B. Each of the transverse walls 6A extends in the row direction in a position opposite the bus electrodes Xb and Yb backing on each other in between the respective row electrode pairs (X, Y) positioned alongside each other. Each of the vertical walls 6B extends in the column direction in a position opposite to the midpoint between the adjacent transparent electrodes Xa and between the adjacent transparent electrodes Ya which are arranged at regular intervals along the corresponding bus electrodes Xb and Yb of the respective row electrodes X, Y. The partition wall 6 is thus shaped in a grid pattern of the transverse walls 6A and the vertical walls 6B so as to define discharge cells C in a one-to-one correspondence with pairs of the transparent electrodes Xa and Ya opposed to each other with the discharge gap g in between in each row electrode pair (X, Y).
The partition wall 6 for partitioning the discharge space into the discharge cells C is conventionally formed of electric insulation materials. For example, a partition-wall material such as a glass paste is coated in a thick film on the back glass substrate 4, then dried. After that, the resulting partition-wall materials is cut into a grid pattern by a sandblasting process using a mask of a predetermined pattern, and then is burned to form the partition wall 6.
The conventional method of forming the partition wall by use of sandblasting has the complicated manufacturing process and therefore gives rise to the problem of a low level of productivity and increased manufacturing costs.
For this reason, instead of the conventional partition wall obtained by forming the insulation material, using a metal-made partition wall covered by an insulation layer has been studied.
However, using the metallic partition wall in the PDP gives rise to the problem of an increase in the electrostatic capacity in the panel and an increase in reactive power associated therewith, leading to an increase in electrical power consumption. Hence, the use of metallic partition wall is not yet commercially practical at present.